As I left rehearsal for my new play the other day, I had a very strange feeling. As I navigated Manhattan's grid from midtown west to my apartment on the Lower East Side, it dawned on me: it was strange to be premiering a play in New York instead of London. Although my last two plays, Dying City and Now or Later, both got their starts at the Royal Court, two of my other six plays have premiered in New York. I recognised the obvious differences back then, in 2005 and 2002: the longer preview period in New York (up to a month before critics come), my hometown's older audiences and steeper ticket prices, the prevalence of a subscription or membership model in our big theatres versus what happens in London.

But this strange feeling didn't have to do with those factors. So what was it, then? As I neared home it dawned on me: New York actors and directors are much more directly critical of a new play in rehearsals than London actors and directors are. In London, I cannot remember a single moment when an actor openly criticised – even implicitly – my text. Any note a director gave me was given privately, quietly and tentatively.

Of course I don't know if actors privately expressed their concerns to directors, who then passed notes on to me – entirely possible. But even there, the critiques have been much more mild than what I've experienced here. Even getting notes at all on the text is, in my experience, a rare thing: when an actor asked me during an early Now or Later rehearsal if I was planning to make any script changes, I said that I was open to the idea, but that I also felt that it was best to treat the text as a jail from which no one can escape; all of us need to find the best way to live in it. The actor didn't miss a beat and replied, "I agree completely."

It's entirely possible that my experience is idiosyncratic – but recently I had lunch with a British writer who was confused by the fact that he was getting rewrite suggestions for his play in its New York premiere, despite the fact that it had debuted in London to near-universal acclaim. Fascinatingly, some months later I had a meeting with the American director of the production. He said that although he loved the play, he felt it had needed some highly specific, precise rewrites. When I asked him why that was, he chalked it up to a play's second production coming with the burden of previous acclaim, and not being able to take anyone by surprise.

Fair enough. But, thinking back on that conversation and my own experience, I wonder if something deeper is going on. I wonder if Londoners simply like the theatre more than New Yorkers. Consider: Transitions between scenes that never once felt problematic in London seen as agonisingly long, boring, momentum-stopping crises in New York; plays that felt brisk at 100 minutes in London feeling five minutes too long at 95 in New York; monologues that were full of drama in London feeling strangely inert here. It might be argued that British culture has always viewed theatre as central in a way American culture does not; the British (and I say this as an American) are more literate and verbal and appreciate the emphasis on spoken language in the theatre in a way that Americans, a visually-oriented people, do not. Are the British even less critical because they are paying less?

Generalisations all, but perhaps with a grain of truth. Maybe, too, American actors and directors know that their theatregoers are impatient. They sense a reluctance to give themselves over to someone else's self-expression – whereas in London, the greater ease at being a part of a group means the actors and director assume a generous audience, not an always-potentially-dissatisfied one.

I am a lucky playwright – I've had great productions of my work in both London and New York, and great audiences in both cities too. But there's no denying that the productions have been very different – even when directed by the same person, as happened when James Macdonald directed Dying City in separate productions. When a British director who loved the play in London saw the Lincoln Center production, he had a very hard time putting into words why he wasn't as moved by it. The fact is, it wasn't meant for him. Both productions were magnificent; maybe both could only have happened in the city in which they came to life.